Laparoscopic surgery is one type of minimally invasive surgery in which a surgeon uses numerous trocar ports to access a tissue site of interest within the abdominal cavity of a patient. The benefits of laparoscopic surgery, as compared to open incisional, abdominal surgery, include less pain, shorter recovery time, less scarring, and lower cost. Endoscopic surgery affords another way to access the abdominal cavity via natural openings (mouth, anus, vagina, urethra) of the body and through the peritoneal lining of the abdominal cavity. Obviously, the size and shape of instruments that may be passed through a body lumen in order to perform a medical procedure in the abdominal cavity are greatly restricted due to the anatomical properties of the lumen.
General surgeons, gastroenterologists, and other medical specialists routinely use flexible endoscopes for intralumenal examination and treatment of the upper gastrointestinal (GI) tract, via the mouth, and the lower GI tract, via the anus. In these procedures, the physician advances the flexible endoscope through the lumen, periodically pausing to articulate the distal end of the endoscope using external control knobs, to redirect the distal tip of the endoscope. In this way, the physician may navigate the tortuous passageway of the upper GI past the pharynx, through the esophagus and gastro esophageal junction, and into the stomach. The physician must take great care not to injure the delicate mucosal lining of the lumen, which generally may stretch open to a diameter in the range of about 15-25 mm, but normally has a non-circular cross sectional configuration when relaxed.
During such translumenal procedures, a puncture must be formed in the stomach wall or in the gastrointestinal tract to access the peritoneal cavity. One device often used to form such a puncture is a needle knife which is inserted through the working channel of the endoscope, and which utilizes energy to penetrate through the tissue. A sphinctertome can then be inserted and reinserted into the tissue to expand the puncture made by the needle knife to form a multidirectional incision in the tissue. While effective, such a procedure for forming multidirectional incisions in tissue is time consuming and can also cause unnecessary distress to the tissue.
Accordingly, there remains a need for improved surgical cutting devices.